Hypnotherapy has been tried by some as a way to drop their smoking habit. / AP/Isaac Brekken

by Karen Weintraub, Special for USA TODAY

by Karen Weintraub, Special for USA TODAY

Amy Lavieri's New Year's resolution for 2013 was to finally lose the extra weight she'd been carrying for a decade.

She'd repeatedly failed at diets and gym memberships, so the Watertown, Mass., resident resolved to give hypnotism a try. One year and a dozen-or-so hypnotherapy sessions later, she's 50 pounds lighter.

"If I look back to last year at this point to where I am this year, it's been a complete 180," she says.

Hypnotism has been around since the mid-19th century, when it was often used as a parlor trick. Today, hypnotherapy is commonly used to break unhealthy habits like smoking, to rid people of phobias and to treat panic attacks.

Anecdotal success stories like Lavieri's abound, and studies have found it effective for behavioral change, as well as for reducing surgical and cancer pain, nausea and fatigue in conjunction with other treatments. Data is weaker for quitting smoking, with one 2010 study finding that hypnotherapy did not do a better job of helping people quit than other interventions or no treatment at all.

"It's something that's often worth trying to find, is it a little bit effective for me, or is it a lot effective, or not at all," says Guy Montgomery, director of Integrative Behavioral Medicine at Mount Sinai Hospital in New York City.

Unlike the stereotype from old movies, hypnotherapy does not put people to sleep and old pocket watches are not involved. Instead, the client, with closed eyes, is guided through a series of relaxing imagery and ideas.

Everyone responds slightly differently to hypnosis, with some slipping into a deep, sleep-like trance and others not feeling much different than having their eyes closed.

"How often during the day do we zone out or drift off? That's a light trance state," says Tom Nicoli, a consulting hypnotherapist and trainer in Massachusetts and New Hampshire, who helped launch World Hypnotism Day a decade ago.

Hypnotherapists use this state to give clients suggestions, like "resist the urge to smoke," or to take them back to past experiences, such as the first time they were scared by a spider.

Benjamin Kligler, research director of the Beth Israel Department of Integrative Medicine Continuum Center for Health and Healing in New York City, used self-hypnosis to quit smoking himself and now treats others.

A primary care doctor who uses mind-body techniques, nutrition and lifestyle modifications in addition to hypnotherapy, Kliger estimates that in 3-6 sessions he helps 60%-70% of the people who come to him for smoking cessation. But he won't treat someone unless he's convinced they really want to quit.

Most of what he does, he says, is train his patients to treat themselves.

"Self-hypnosis is the really key part, because you get to a point where you're going to have that craving â?? you just have to be able to give yourself the message: 'It's no longer an option.'"

Insurance almost never covers hypnosis, so clients must pay out of pocket for fees that range as high as Kliger's $250 a session â?? for as few as three sessions or more than a dozen, depending on the complexity of the problem.

Brian Mahoney, Lavieri's hypnotherapist, says he will only work with people who understand that hypnotism is not magic. He doesn't work miracles in one session; success comes, as with Lavieri, after weeks or months of hard work.

Lavieri, who met with Mahoney twice a month for the first half of 2013 and less often since, says she was very skeptical about hypnotism at first. "I did initially call with the sense of 'why not, I've tried everything else?'" But she got more comfortable when she realized that she felt very focused when hypnotized and always knew what was going on around her.

"I found it extremely successful in understanding a lot that maybe I had slipped under the rug for many years," she says.

Lavieri's resolution for 2014? To use hypnotism to help keep off the weight.

"This is the first time in a long time I'm optimistic I can maintain this and not have weight issues any more," she says.

Finding a good hypnotist:

There is no national licensing board for hypnotherapists. Some practitioners are doctors or psychologists with extra training and the skills to use hypnotherapy in conjunction with other treatments; others have no more professional training than a weekend seminar.

To decide if a hypnotherapist is right for you:

* Do some Internet research, seeing how they present themselves online and checking review sites like Yelp (though remember that not all reviews are legitimate).

* Get personal references from people you trust.

* Talk to the hypnotherapist on the phone before scheduling a session, to see how they come across, and to ask about training and experience.